Traction current and traction backflow composite channel

Abstract

The invention relates to a traction current and traction backflow composite channel which comprises a traction current channel composed of a plurality of metal wires. The traction backflow channel is composed of a plurality of metal wires, the traction backflow channel is evenly arranged on the periphery of the traction current channel, and the current direction of the traction current channel is opposite to that of the traction backflow channel; the insulating layer is arranged between the traction backflow channel and the traction current channel, uniformly coats the outer surface of the traction current channel and is uniformly attached to the inner surface of the traction backflow channel; according to the invention, the positive cable and the negative cable are integrated in the composite channel, and the advantages that the current directions of the positive cable and the negative cable are opposite and the distance is short are utilized, so that the electromagnetic induction of the positive cable and the negative cable can offset each other, and the electromagnetic induction influence range is greatly reduced; and the electromagnetic influence of the traction network on surrounding electrical equipment is fundamentally reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cables, in particular to a traction current and traction return composite channel. Background Art

[0002] At present, the commonly used power supply methods for electrified railways are direct power supply with return line (DN power supply) and autotransformer power supply (AT power supply). Under these two power supply methods, negative cables are used to introduce traction return current into the substation, and positive cables are used to transmit traction current to the contact network. The negative cable and the positive cable have exactly the same structure. As relatively independent individuals, the positive and negative cables will have electromagnetic effects on adjacent high-voltage cables in certain special scenarios, causing the induced voltage of the metal layer of the high-voltage cable to exceed the design benchmark, which may cause the metal layer to short-circuit to the ground and cause electrical failures.

[0003] Electrified railways use single-phase AC power to supply the traction network. The traction network is an asymmetric power supply circuit, consisting of a contact network, rails, the earth and return lines. It is bound to generate an electromagnetic field around it, which will affect the surrounding electrical equipment. At present, there are two main ways to solve the problem. One is to strengthen shielding measures for the affected equipment or move it away from the affected area, and the other is to take measures to suppress interference in power supply. However, these measures are costly and have a wide range of impact, and cannot fundamentally and effectively reduce the electromagnetic impact of the traction network on the surrounding electrical equipment. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the positive and negative cables, as relatively independent individuals, have a large electromagnetic influence on surrounding electrical equipment, and thus provide a traction current and traction return composite channel. By integrating the positive cable and the negative cable in a composite channel, and utilizing the advantages that the current directions of the positive cable and the negative cable are opposite and the distance is close, the electromagnetic induction of the positive cable and the negative cable can not only offset each other, but also greatly reduce the scope of influence of the electromagnetic induction, thereby fundamentally reducing the electromagnetic influence of the traction network on the surrounding electrical equipment.

[0005] In order to solve the above technical problems, the present invention provides a traction current and traction return composite channel, comprising:

[0006] A traction current channel, which is composed of multiple metal wires;

[0007] A traction return channel, which is composed of a plurality of metal wires, and the traction return channel is evenly arranged around the traction current channel, and the current directions of the traction current channel and the traction return channel are opposite;

[0008] An insulating layer is arranged between the traction return channel and the traction current channel, and the insulating layer uniformly covers the outer surface of the traction current channel and uniformly adheres to the inner surface of the traction return channel.

[0009] In one embodiment of the present invention, it further includes an inner shielding layer located between the insulating layer and the traction current channel, wherein the inner shielding layer uniformly covers the outer surface of the traction current channel and is uniformly attached to the inner surface of the insulating layer.

[0010] In one embodiment of the present invention, it further includes an outer shielding layer located between the insulating layer and the traction return channel, wherein the outer shielding layer is uniformly coated on the outer surface of the insulating layer and uniformly attached to the inner surface of the traction return channel.

[0011] In one embodiment of the present invention, the inner shielding layer is composed of a semi-conductive inner shielding material, and the outer shielding layer is composed of a semi-conductive outer shielding material.

[0012] In one embodiment of the present invention, a protective layer is further included between the outer shielding layer and the traction return channel, wherein the protective layer is uniformly coated on the outer surface of the outer shielding layer and uniformly attached to the inner surface of the traction return channel.

[0013] In one embodiment of the present invention, the protective layer is configured as a semiconducting water-resistant tape.

[0014] In one embodiment of the present invention, the traction return channel includes a first traction return channel and a second traction return channel, and the second traction return channel is evenly covered on the outer surface of the first traction return channel.

[0015] In one embodiment of the present invention, it also includes a first auxiliary layer and a second auxiliary layer, the first auxiliary layer and the second auxiliary layer are made of metal or semi-conductive tape, the first auxiliary layer is located between the first traction return channel and the second traction return channel, and the second auxiliary layer is uniformly coated on the outer surface of the second traction return channel.

[0016] In one embodiment of the present invention, the insulating layer is composed of cross-linked polyethylene insulating material.

[0017] In one embodiment of the present invention, the sum of the cross-sectional areas of the plurality of metal wires of the traction current channel is equal to the sum of the cross-sectional areas of the plurality of metal wires of the traction return channel.

[0018] The above technical solution of the present invention has the following advantages compared with the prior art:

[0019] The traction current and traction return composite channel of the present invention integrates the traction current channel and the traction return channel in the composite channel, which not only realizes the function of power supply and return for the contact network, but also limits the electromagnetic induction of the traction current channel and the traction return channel to a small range, thereby reducing the impact on surrounding electrical equipment; after the traction current channel and the traction return channel are integrated into a composite channel, the opposite current directions of the traction return channel and the traction current channel are utilized to greatly enhance the mutual offset effect of the electromagnetic induction of the two, thereby improving the problem that the original positive cable and negative cable have a large electromagnetic impact on surrounding electrical equipment; the traction current channel and the traction return channel are integrated into a composite channel, thereby improving the laying efficiency and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0021] Figure 1 It is a structural schematic diagram of a front cross-sectional view of the traction current and traction return composite channel of the present invention;

[0022] Figure 2 for Figure 1 A schematic structural diagram of a side cross-sectional view of a traction current and traction return composite channel shown;

[0023] Figure 3 for Figure 1 A local enlarged view of the A portion of the traction current and traction return current composite channel shown;

[0024] Explanation of the figure marks in the specification: 1. traction current channel; 2. inner shielding layer; 3. insulation layer; 4. outer shielding layer; 5. protective layer; 6. traction return channel; 61. first traction return channel; 62. second traction return channel; 7. auxiliary layer; 71. first auxiliary layer; 72. second auxiliary layer. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0026] Example

[0027] Reference Figure 1 and 2 As shown, in one embodiment of the present invention, a traction current and traction return composite channel is disclosed, which is used on an electrified railway to transmit traction current and return from a substation to the contact network of the electrified railway. The composite channel includes:

[0028] The traction current channel 1 is formed by twisting or bundling a plurality of metal wires, one end of which is connected to the low-voltage side of the transformer of the substation, and the other end is connected to the grid disconnector, and is used to transmit the traction current from the substation to the contact network; the metal wire is preferably a round copper conductor;

[0029] The traction return channel 6 is composed of a plurality of metal wires, and the metal wires are preferably electrical round copper wires. The traction return channel 6 is evenly arranged around the traction current channel 1. One end of the traction return channel 6 is connected to the rail, and the other end is connected to the neutral point of the transformer, and is used to conduct the traction return collected by the track, the return line and the earth back to the substation; when in use, the current directions of the traction current channel 1 and the traction return channel 6 are opposite, so that the electromagnetic fields generated by the traction return channel 6 and the traction current channel 1 can offset each other, greatly reducing the electromagnetic impact of the composite channel on the surrounding electrical equipment, as shown in reference Figure 2 The arrow points to the direction of current flow;

[0030] The insulating layer 3 is arranged between the traction return channel 6 and the traction current channel 1 to achieve insulation between the two and prevent circuit short circuit; further, the insulating layer 3 uniformly covers the outer surface of the traction current channel 1 to achieve close bonding of multiple conductive metal wires of the traction current channel 1; and is uniformly attached to the inner surface of the traction return channel 6.

[0031] In one embodiment of the present invention, referring to Figure 1 As shown, it also includes an inner shielding layer 2 located between the insulating layer 3 and the traction current channel 1, the thickness of the inner shielding layer 2 is less than the thickness of the insulating layer 3, the inner shielding layer 2 is uniformly coated on the outer surface of the traction current channel 1, and is uniformly attached to the inner surface of the insulating layer 3, and the inner shielding layer 2 is used to eliminate the increase in electric field strength caused by the rough surface of the traction current channel 1.

[0032] In one embodiment of the present invention, referring to Figure 1 As shown, it also includes an outer shielding layer 4 located between the insulating layer 3 and the traction return channel 6. The thickness of the outer shielding layer 4 is less than the thickness of the insulating layer 3. The outer shielding layer 4 is uniformly coated on the outer surface of the insulating layer 3 and is uniformly attached to the inner surface of the traction return channel 6. The outer shielding layer 4 is used to make the electric field on the outer surface of the insulating layer 3 uniform and protect the insulating layer from damage.

[0033] In one embodiment of the present invention, referring to Figure 1 As shown, the inner shielding layer 2 is composed of a semi-conductive inner shielding material, and the outer shielding layer 4 is composed of a semi-conductive outer shielding material. Both the semi-conductive outer shielding material and the semi-conductive inner shielding material can improve the electric field distribution of the composite channel, making the electric field distribution more uniform and avoiding local electric field distortion.

[0034] In one embodiment of the present invention, referring to Figure 1 As shown, it also includes a protective layer 5 located between the outer shielding layer 4 and the traction return channel 6. The protective layer 5 is uniformly coated on the outer surface of the outer shielding layer 4 and uniformly attached to the inner surface of the traction return channel 6. The protective layer 5 is used to prevent moisture and other liquids from penetrating into the composite channel, reducing the risk of leakage, and protecting the outer shielding layer 4 from damage.

[0035] In one embodiment of the present invention, the protective layer 5 is configured as a semiconducting resistive water belt, which is in contact with the traction return channel 6 to maintain the same potential between the two.

[0036] In one embodiment of the present invention, referring to Figure 3 As shown, in order to ensure that the outer diameter of the traction return channel 6 is uniform, the traction return channel 6 includes a first traction return channel 61 and a second traction return channel 62. The second traction return channel 62 is uniformly coated on the outer surface of the first traction return channel 61. In terms of the process flow, a first layer of metal wire is uniformly wrapped on the outer surface of the protective layer 5 to form a first traction return channel 61, and then a second layer of metal wire is wrapped on the outer surface of the first layer of metal wire to form a second traction return channel 62.

[0037] In one embodiment of the present invention, referring to Figure 3 As shown, it also includes a first auxiliary layer 71 and a second auxiliary layer 72. The first auxiliary layer 71 is located between the first traction return channel 61 and the second traction return channel 62. The first auxiliary layer 71 is coated on the outer surface of the first traction return channel 61 to improve the structural stability of the first traction return channel 61; the second auxiliary layer 72 is uniformly coated on the outer surface of the second traction return channel 62, and the second auxiliary layer 72 is used to improve the structural stability of the second traction return channel 62; further, the first auxiliary layer 71 and the second auxiliary layer 72 use metal or semi-conductive tapes to form a conductive whole with the traction return channel 6.

[0038] In one embodiment of the present invention, the insulating layer 3 is composed of cross-linked polyethylene insulating material.

[0039] In one embodiment of the present invention, the sum of the cross-sectional areas of the multiple metal wires of the traction current channel 1 is equal to the sum of the cross-sectional areas of the multiple metal wires of the traction return channel 6, which makes the current paths of the traction current channel 1 and the traction return channel 6 more symmetrical, thereby reducing the impact of the electromagnetic field on surrounding equipment.

[0040] The working principle of the traction current and traction return composite channel of the present invention is:

[0041] At one end of the composite channel, the traction current channel 1 is connected to the low-voltage side of the substation transformer, and the traction return channel 6 is connected to the neutral point of the transformer. At the other end of the composite channel, the traction current channel 1 is connected to the grid-connected disconnector, and the traction return channel 6 is connected to the rail. When supplying power, the traction current of the substation is conducted from the traction current channel 1 to the contact network to realize power supply. Finally, the traction return current collected from the track, the return line and the earth is conducted back to the substation through the traction return channel 6. Since the traction return channel 6 and the traction current channel 1 are integrated in the composite channel, the electromagnetic induction of the two is limited to a small range, and the impact on the surrounding electrical equipment is small. In addition, the currents of the traction return channel 6 and the traction current channel 1 are opposite, so that the mutual offset effect of the electromagnetic induction of the two is greatly enhanced, further reducing the electromagnetic impact on the surrounding electrical equipment.

[0042] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A traction current and traction return composite channel, characterized in that: include, A traction current channel, which is composed of multiple metal wires; A traction return channel, which is composed of a plurality of metal wires, and the traction return channel is evenly arranged around the traction current channel, and the current directions of the traction current channel and the traction return channel are opposite; An insulating layer is arranged between the traction return channel and the traction current channel, and the insulating layer uniformly covers the outer surface of the traction current channel and uniformly adheres to the inner surface of the traction return channel.

2. A traction current and traction return composite channel according to claim 1, characterized in that: It also includes an inner shielding layer located between the insulating layer and the traction current channel, wherein the inner shielding layer uniformly covers the outer surface of the traction current channel and is uniformly attached to the inner surface of the insulating layer.

3. A traction current and traction return composite channel according to claim 2, characterized in that: It also includes an outer shielding layer located between the insulating layer and the traction return channel. The outer shielding layer is evenly coated on the outer surface of the insulating layer and evenly attached to the inner surface of the traction return channel.

4. The traction current and traction return composite channel according to claim 3, characterized in that: The inner shielding layer is composed of a semi-conductive inner shielding material, and the outer shielding layer is composed of a semi-conductive outer shielding material.

5. The traction current and traction return composite channel according to claim 3, characterized in that: It also includes a protective layer located between the outer shielding layer and the traction return channel. The protective layer is evenly coated on the outer surface of the outer shielding layer and evenly attached to the inner surface of the traction return channel.

6. The traction current and traction return composite channel according to claim 5, characterized in that: The protective layer is configured as a semi-conductive water-resistant tape.

7. The traction current and traction return composite channel according to claim 1, characterized in that: The traction return channel includes a first traction return channel and a second traction return channel, and the second traction return channel is evenly covered on the outer surface of the first traction return channel.

8. The traction current and traction return composite channel according to claim 7, characterized in that: It also includes a first auxiliary layer and a second auxiliary layer, the first auxiliary layer and the second auxiliary layer are made of metal or semi-conductive tape, the first auxiliary layer is located between the first traction return channel and the second traction return channel, and the second auxiliary layer is uniformly coated on the outer surface of the second traction return channel.

9. The traction current and traction return composite channel according to claim 1, characterized in that: The insulating layer is composed of cross-linked polyethylene insulating material.

10. The traction current and traction return composite channel according to claim 1, characterized in that: The sum of the cross-sectional areas of the plurality of metal wires in the traction current channel is equal to the sum of the cross-sectional areas of the plurality of metal wires in the traction return channel.

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